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  <title>Document</title>
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<script>
  var arr = function (n) {
    if (n == 1) return 0
    var sum = 0
    for (var i = 2; i <= n; i++) {
      while (n % i == 0) {
        sum += i
        n = n / i
      }
    }
    return sum
  };
  console.log(arr(n = 3));
</script>

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